In wireless communication networks, the multi-user full-duplex multiple-input multiple-output (MIMO) protocol utilized for transmission and reception of signals transmitted within the same frequency band has received increased recognition as a promising technique to increase network spectral efficiency. A benefit of the multi-user full-duplex MIMO protocol is to facilitate a communication network's ability to receive signals from multiple uplink user devices and send signals to multiple downlink user devices simultaneously. A downside consequence associated with utilizing the full-duplex signal protocol is the creation of self-interference between incoming and outgoing signals (i.e., transmitters and receivers) of a base station, which contaminates the incoming signals and deteriorates the performance of the network.
In addition to interference issues related to transceivers of a base station, the multi-user full-duplex MIMO protocol of communication networks also presents interference issues between mobile devices that send signals (e.g., uplink user devices) to, or receive signals (downlink user devices) from, a base station. Particularly, downlink user devices can suffer from interference caused by the transmission of signals sent by uplink user devices located within a defined communication range of the downlink mobile devices. Given such problems, ambiguity exists around the question of how to fully realize multi-user MIMO full-duplex communication networks.
Currently, there are a few approaches to remedy the self-interference issue, however, each approach falls short of eliminating self-interference. One proposed approach referred to as temporal cancellation includes replicating an interfering signal and subtracting the replicated signal from the received signal at a base station. Another proposed approach implements a 2-stage iterative echo canceller at a receiver of a base station to boost the overall throughput of a received signal. Another approach includes the exploitation of spatial degrees of freedom between antennas that transmit signals (e.g., transceiver of a base station) and antennas that receive signals (e.g., antenna of a mobile station) in order to alter space-time processing of signals in an effort to suppress self-interference of signals in communication networks.
Most of the existing approaches consider the scenario of point-to-point communication (e.g., backhaul link), while the benefits of full-duplex communication in multi-user access network have not been fully exploited. In this regard, there is a significant need for devices, systems and methods to increase the data rate in multi-user networks that utilize a full-duplex MIMO protocol.